"This paper presents an experiment that sought to investigate opinions and attitudes towards assistive robots by French people, users and future users. 217 participants were recruited. They were divided into four age groups: 67 children (/M/ age= 9.2 years), 35 teenagers (/M/ age= 14.5 years), 37 young adults (/M/ age= 22.2 years), and 28 seniors (/M/ age= 68.3 years). Each participant was individually asked to perform three tasks: first, s/he was asked to explain what is a robot to her/him; second, s/he was asked to complete our French version of the Negative Attitudes Towards Robots Scale (NARS); third, s/he was asked to classify eight robots shown in videos. The main results obtained were as follows: spontaneously, a robot is defined according to three dimensions, /i.e/., its qualities (or properties), its physical appearance, and its usefulness; there is a significant impact of the age on “naïve” mental representations of robots; there is no impact of gender on attitudes and preferences; younger respondents (children) rated significantly more positive attitudes towards robots than the other age group (teenagers, young adults, and seniors); our French version of NARS is validated for French adults, but NARS does not seem to be adapted to young people. Regardless of age and gender, participants preferred robots that had animal-like shapes and/or are small humanoid robots; robots with anthropomorphic or humanoid characteristics were less preferred. Implications for the design of future assistive robots are discussed."